The contagious cancer, known as facial tumor disease, is found only in Tasmanian devils -- notoriously cantankerous animals now found in the wild only on the island of Tasmania. The cancer is spread through biting, which is common among devils during mating and feeding.

It kills infected animals within 6 to 12 months. There's no known vaccine or cure.

Since the disease emerged, devil populations in the wild have declined by about 80 percent, according to the researchers.

"We are now dealing with very small and potentially isolated groups of devils across Tasmania," lead researcher Billie Lazenby, a wildlife biologist with the Save the Tasmanian Devil Program, said in a new release from San Diego Zoo Global.

"The ongoing impact of [the disease], which continues to cause high mortality in devils, could make them vulnerable to other threats," she said.

The researchers also found that remaining wild populations of Tasmanian devils are showing some reproductive changes, possibly in response to the disease.

"Devils in diseased areas are now breeding younger and having more pouch young, which has allowed them to persist at low levels in the wild," Mathias Tobler, a population sustainability scientist with San Diego Zoo Global, said in the news release. Tasmanian devils are marsupials -- animals that carry their young in pouches.

"This research has shown the structure of the wild devil populations in diseased areas has shifted dramatically, with devils over the age of 2 being very rare, compared to sites before [the disease] emerged," Tobler said. "Earlier breeding in young devils means that they are contracting [the disease] younger, often as 1-year-olds."

Though breeding at an earlier age has enabled wild populations of devils to continue, their low numbers make extinction more likely.

"Such large reductions in their numbers and the change in their age structure means their populations are impacted more by other threats," David Pemberton, program manager for the Save the Tasmanian Devil Program, said in the news release. Those threats, he said, include "roadkill, bushfire, loss of genetic diversity, variation in food availability caused by drought and changes in the ecosystem as it responds to the loss of devils in the wild."

"Efforts to manage the devils, such as the development of an immunotherapy, are ongoing, but remain in a research-and-development phase," he said.

The research was published online recently in the Journal of Applied Ecology.